It has got the go-ahead to build its first prototype ‘green grass mill’ in Hampshire, which will use anaerobic digestion to convert grass into biogas and fertiliser.

Instead of being burnt to create electricity, the biogas will be “scrubbed” to create biomethane, which can be fed directly into the national gas network instead of fossil fuel methane.

Each 5MW gas mill would require 2,500 acres of grassland and power 2,500 homes. Around 5,000 mills would need to be built to supply 97% of homes.

Dale Vince, Founder of Ecotricity, said: “Recently, it’s become possible to make green gas and put it into the grid, in the same way we’ve been doing with green electricity for the last two decades. The current way of doing that is through energy crops and food waste – but both have their drawbacks.

“Through our research, we’ve found that using grass is a better alternative and has none of the drawbacks of energy crops, food waste or fracking – in fact, it has no drawbacks at all.”